tony: Heheh thanks fella! I've spent hours gawping at your work over the years so it's nice to return the favour!

As for a tutorial, I don't have anything written down really. Are you talking for the renders of the leaf blower guy for instance? I model everything out in maya so I have a nice clean base then sculpt in Zbrush at lower subdivisions for the most part to keep things nice and clean using inflate and flatten brushes most of the time. Then I render out a bunch of passes (shadows, ao, depth etc.) in Zbrush BPR and then composite them in photoshop. Feel free to email me if you have any specific questions.